The invention is directed to a card connector for connecting a printed circuit board and a card and, more particularly, to such a card connector equipped with means for preventing electric circuits from being broken electrostatically when an electric connection is made between a printed circuit board and a card.
As is known, when it is desired to make an electric connection is between an electronic device having a printed circuit board and a card having an integrated circuit, a card connector can be used to make the connection between the card and the printed circuit board simply by inserting the card in a card connector.
Such a card connector typically includes an insulating housing having a pair of guide sections to guide the card into a mating position with the card connector. Also, the card connector may have means to disconnect and eject the card therefrom, and a card-protecting shell to prevent the card from any exterior hazards.
When a person inserts a card in the card connector by hand, there is a fear of the integrated circuit of the card and/or the printed circuit board of the electronic device being electrostatically destroyed by permitting static electricity to be discharged from the hand to the card and/or the electronic device. To prevent such an electrostatic hazard, the card connector can include grounding means to allow static electricity to be discharged from the person to the grounding circuit of the printed circuit board of the electronic device.
Typically, such a grounding means comprises a contacting section that makes contact with an electrically conductive shield which surrounds the top, bottom and opposite sides of the connector-mating section of the card, and a separate grounding section that makes an electric connection between the contacting section and the grounding circuit of the printed circuit board of the electronic device.
Such grounding means, however, is not effective if a good electric connection is not made between the contacting section and the grounding section. The contacting section of the grounding means may be integrally formed to project in a cantilever fashion from the card-ejection means or slider (both made of electrically conductive material) or from the metal shell of the card connector. The cantilever-like projection of the card-ejection means or slider is made to slide on a grounding member of the card when the card is inserted in the card connector. This arrangement may eventually cause a poor electric connection between the cantilever-like projection and the card grounding member particularly in applications where the card connector is used for repeated insertions of a card.
As is known, there is an ever increasing demand for reducing the physical size and manufacturing cost of such card connectors. However, to meet this demand, there is a corresponding risk of lowering the reliability of the anti-electrostatic hazard means. Such a grounding means is assembled from two separate parts (i.e., contacting section and grounding section), and accordingly the assembly and manufacturing costs can be high.
An object of the present invention is to provide a small-sized card connector whose anti-electrostatic hazard reliability is substantially improved in spite of reducing significantly the manufacturing cost. To obtain this object, a card connector for use in making a required electric connection between a printed circuit board and a card having an integrated circuit, the card connector including an insulating housing comprising a connector section which mates with a mating connector section of the card, a pair of guide sections to guide the mating connector section of the card to the connector section of the card connector and grounding means to ground the card to the grounding conductor of the printed circuit board via the card connector, is improved according to the present invention in that the grounding means is provided in at least one of the guide sections; and the grounding means comprises a resilient contact comprising:
a contact section projecting in the guide slot of the guide section, wherein opposite guide slots face toward each other to accommodate opposite longitudinal sides of the card in guiding the mating connector section of the card to the connector section of the card connector, thus permitting the projecting contact section to contact at least one longitudinal side of the card; and
a grounding section integrally connected to the contact section, which grounding section is adapted to be connected to the grounding circuit of the printed circuit board.
The resilient contact comprises a contact section and a grounding section integrally connected to the contact section, such an integral structure effectively eliminates the possibility of causing insufficient grounding that would occur if the grounding structure were made of separate parts. Such possibility of incomplete grounding would be increasingly noticeable as the size of the card connector is decreased. The use of the integral grounding structure, therefore, contributes to the down-sizing of the card connector.
The resilient contact may comprise a contact section and a grounding section integrally connected thereto, and may be fixed by inserting a contact-to-grounding transitional base of the resilient contact into the seat of one of the guide sections, the seat having an opening to permit the contact section of the contact to project into the guide slot.
The grounding section of the resilient contact comprises a planar fitting nail adapted to be surface soldered to the grounding circuit of the printed circuit board.
Other objects of the present invention will be understood from the following description of a card connector according to a preferred embodiment of the present invention.